This is the most stupid reason to ruin someone's Christmas!
As much as I hate Iberia I would not believe anything like happening to anyone. I have a number of flights booked with Amex, which since then got replaced with a new card number - I hope I won't get similar issues to yours!
Dealing with a thirdparty services at outstations is always not easy - they usually underpaid, under trained, without much experience, they lack of common sense and empathy and follow rules strictly.